64 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. I48 



ing up to five on fold, one fewer in sulcus (normally an odd number: 

 median crest counted as costa) ; valve edges butting around anterior 

 margin, strongly overlapping at posterior in some species ; stolidium 

 entirely absent ; growth lines weak, closely spaced ; growth laminae 

 slightly stronger. 



Pedicle valve moderately strongly convex, slightly swollen in um- 

 bonal region; beak thick, bluntly pointed, strongly curved against 

 brachial umbo, closing delthyrium and foramen ; beak ridges absent. 



Brachial valve more strongly convex transversely, moderately con- 

 vex longitudinally along crest of fold ; beak not swollen, apex within 

 pedicle valve. 



Pedicle valve interior with thick dental plates uniting at midline to 

 form deep spondylium, elevated on low median septum duplex, extend- 

 ing anteriorly about one-third length of valve ; spondylium wall becom- 

 ing thinner toward anterior. 



Brachial valve interior with well-developed cardinal process at 

 posterior apex of hinge plate ; crura extending anteriorly from edge of 

 hinge plate ; camarophorium elevated for entire length, formed by 

 spreading of upper edges of thick median septum duplex (each wing of 

 camarophorium formed of one plate) ; intercamarophorial plate thick, 

 duplex, extending from midline of posterior part of camarophorium to 

 underside of hinge plate, continuing anteriorly for short distance be- 

 yond hinge plate ; median septum extending anteriorly about one-third 

 length of shell, camarophorium extending somewhat farther. 



Type species. — Camerisma prava Grant n. sp. 



Additional species assigned to Camerisma. — 

 Camerisma girtyi n. sp. 

 Camerisma sagmaria n. sp. 

 ? Pentamerus sella Kutorga 1844 



Camarophoria sella (Kutorga) of Licharev & Einor, 1939 (non Kutorga) 

 ? Camarophoria pentameroides Tschernyschev 1902; Ivanova, 1949; Sary- 

 cheva and Sokolskaya, 1952. 



The two questioned species are assigned tentatively to Camerisma 

 on the basis of diagnoses and illustrations by Tschernyschev. Presence 

 of the intercamarophorial plate has not been established beyond doubt. 

 See discussion, below. 



Grabau ( 1936) identified specimens from the Maping Limestone of 

 Kweichow, China, with Camarophoria sella and C. pentameroides. 

 Neither of his two species appear to be similar to the Eastern European 

 or Alaskan species, but both might belong to Camerisma. Further 

 study of the Asian species is necessary before their proper place in the 

 Stenoscismatacea can be determined. 



Comparisons. — Camerisma is characterized by its smooth or nearly 

 smooth shell, high vaulted fold, tightly curved pedicle beak, thick shell 



